Systemic light-chain amyloidosis (AL) is a protein conformation disorder due to a clonal plasma cell dyscrasia. There are no established and approved second-line therapies for patients with systemic AL amyloidosis who fail initial melphalan-based treatment, be it high-dose melphalan with stem cell transplant or oral melphalan and dexamethasone (MDex). Therefore new treatments are needed for those who fail initial therapy and for those who initially respond but subsequently relapse.